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United States Patent | 5,530,456 |
Kokubo | June 25, 1996 |
Light rays emitted from light-emitting units pass through a window of a housing and are reflected by a finger pad of a finger. The reflected light rays again pass through the window and are received by light-receiving elements of each of light-receiving units. These light-receiving elements output reflected light detection signals corresponding to the ridges and recesses of the finger pad. From these reflected light detection signals, a wave-shaping unit outputs rectangular wave signals indicating the moving amount of the finger pad and moving direction signals indicating the moving direction of the finger pad for the individual axes.
Inventors: | Kokubo; Kenichi (Tokyo, JP) |
Assignee: | NEC Corporation (Tokyo, JP) |
Appl. No.: | 350890 |
Filed: | December 7, 1994 |
Dec 09, 1993[JP] | 5-308921 |
Current U.S. Class: | 345/175; 345/160 |
Intern'l Class: | G09G 005/08 |
Field of Search: | 345/166,173,175,176,160 250/221 |
4254333 | Mar., 1981 | Bergstrom | 250/221. |
4951034 | Aug., 1990 | Mazzone et al. | 340/710. |
5063289 | Nov., 1991 | Jasinski et al. | 250/221. |